JP2007256251A - Data collection processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data collection processor capable of attaining measurement in a high dynamic range with out increasing the bit number of an A/D converter, capable of converting a nonlinear scale data into a linear scale data without using a complicated arithmetic processing circuit, and capable of integration-processing sampling data obtained in the nonlinear scale, in the data collection processor using the A/D converter. <P>SOLUTION: This data collection processor of ADC system includes a log amplifier 200 in a front stage of the A/D converter 210, a signal amplified by the log amplifier 200 having a nonlinear input/output characteristic is A/D-converted, and the data are integration-processed, while reconverting a voltage value data converted into the nonlinear characteristic, into a data of a linear scale, according to a table memory 20 for reverse log conversion. The known voltage value is input into the log amplifier 200 to conduct the measurement, and the voltage value and the voltage value after converted are stored to calibrate the table memory. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a data collection processing apparatus for a measuring apparatus using an A / D converter (analog / digital converter), and more particularly to a technique effective when applied to a time-of-flight measurement type mass spectrometer.

  For example, a time-of-flight mass spectrometer (TOF-MS: Time Of Flight Mass Spectrometry), which is an example of a measurement device using an A / D converter, ionizes a sample and accelerates it at a constant voltage. It is a device that analyzes the components contained in a sample by measuring the time of flight and signal intensity according to mass and charge. In this TOF-MS, the waveform of the detection signal differs depending on the number of ions detected at one time. Therefore, in order to quantitatively measure the detection signal, an ADC (Analog to Digital Converter) type data collection processing device is used. Generally used. An ADC data collection processing apparatus is an apparatus that uses an A / D converter to sample an ion detection signal, which is an analog signal, at a constant period, and collects digital data indicating time data and voltage values.

  In recent mass spectrometers, the difference in the intensity of ion signals to be measured has increased with the increase in sensitivity of ion detectors. Therefore, an A / D converter that can sample a wide voltage range with high speed and high accuracy is required. However, since a high-speed (1 to 2 Gsps) A / D converter currently on the market has only about 8 to 10 effective bits, in the measurement where the intensity of the detection signal changes by several tens of times or more. There is a problem that the dynamic range (signal intensity resolution) is insufficient and the measurement sensitivity (S / N ratio) is greatly deteriorated.

  Generally, in order to realize an extremely high dynamic range, such a problem is solved by using a plurality of A / D converters. However, when a plurality of A / D converters are used, However, the design man-hours and material costs of high-speed hardware increase, resulting in problems of high cost and long development period.

  In a device such as TOF-MS where the detection signal waveform is not always constant for each measurement, statistical data processing is required to improve the measurement signal detection sensitivity (S / N ratio). It is necessary to perform measurement and integrate measurement data.

  One possible solution without increasing the number of bits with one A / D converter is to increase the dynamic range by providing an amplifier with a non-linear gain characteristic in the previous stage of the A / D converter. .

  However, although measurement with a wide dynamic range can be realized by using a non-linear amplifier, the obtained measurement data is not linear (linear) scale data, and therefore cannot simply integrate the acquired data, such as TOF-MS. It cannot be applied to a data collection processing device that requires the above integration processing.

  Therefore, the present invention solves the problems of the prior art as described above, and an object of the present invention is to provide a non-linear amplifier before the A / D converter in a data collection processing apparatus using the A / D converter. By using it, measurement with a high dynamic range is achieved without increasing the number of bits of the A / D converter, and by using a table memory for reverse log conversion, a complicated arithmetic processing circuit is not used. Another object of the present invention is to provide an ADC type data collection processing device that converts nonlinear scale data into a linear scale and enables integration processing of sampling data obtained by the nonlinear scale.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  In order to achieve the above object, according to a first realization means of the present invention, in an ADC data collection processing apparatus, a log amplifier is provided in front of the A / D converter, and the log having this non-linear input / output characteristic is provided. A / D conversion is performed on the signal amplified by the amplifier, and data integration processing is performed while re-converting the voltage value data converted into nonlinear characteristics into linear scale data according to the table memory for reverse log conversion. is there.

  Further, a gain adjustment circuit having a linear gain characteristic is provided in parallel with the log amplifier, and the data integration process is performed by switching the amplifier to be used depending on the measurement target.

  Next, the second realization means performs measurement by inputting a known voltage value to the log amplifier, and stores the set voltage value and the voltage value data after A / D conversion in the table memory to perform reverse logging. The table memory used for conversion is calibrated.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  According to the present invention, in an ADC data collection processing apparatus used in an analyzer such as TOF-MS, the log amplifier is used in the front stage of the A / D converter, so that the number of bits of the A / D converter is increased. By using a table memory for reverse log conversion, the nonlinear scale data can be converted to a linear scale without using a complicated arithmetic processing circuit. It is possible to provide an ADC-type data collection processing device that can integrate the sampling data obtained in (1).

  In addition, a gain adjustment circuit with linear gain characteristics is provided in parallel with the log amp and can be used by switching depending on the measurement target. Therefore, it is possible to perform high dynamic range measurement or ADC measurement data collection processing. An apparatus can be provided.

  In addition, a gain adjustment circuit with linear gain characteristics is provided in parallel with the log amp, and can be switched and used with a simple configuration, enabling high dynamic range measurement or high accuracy measurement with a single device. is there.

  In addition, a gain adjustment circuit with linear gain characteristics is provided in parallel with the log amp, and can be switched according to the measurement target, enabling high dynamic range measurement or high accuracy measurement with a single device. Since one unit has two roles, it is possible to reduce the cost and size of the apparatus.

  Further, since an amplifier having a linear gain characteristic is provided and the absolute voltage value of the input signal can be measured, it can be used for calibration of the gain characteristic of the external signal generator.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
First, an outline of the configuration and operation of a mass spectrometer (TOF-MS) to which the data collection processing apparatus of the present invention is applied will be described with reference to FIG. FIG. 1 shows an outline of the configuration and operation of a mass spectrometer.

  The mass spectrometer 1 includes an introduction unit 101 that ionizes a sample to be analyzed, a voltage applied to the ionized sample to accelerate the ionization sample, a TOF unit 102 that flies ions toward the detector, and the ions that have flown. It comprises a detector 103 for detection, an ion ejection signal generator 104 for generating an ion ejection signal 104a for determining the timing for accelerating ions, and the like.

  The mass spectrometer 1 controls and acquires the data collection processing device 2 for measuring and collecting the voltage value and time of flight of the ion detection signal 1a generated from the detector 103, and the data collection processing device 2. The CPU 3 for analyzing the processed data 2a, the measurement result and the analysis result 4a are displayed, and the input / output device 4 for the user to control the device is connected.

  In the mass spectrometer 1, the sample to be analyzed is ionized by the introduction unit 101 and sent to the TOF unit 102 simultaneously with the measurement start signal 2b. The ions that have entered the TOF section 102 are applied with a voltage at the timing of the ion launch signal 104a, and fly inside the TOF section 102 in a vacuum state in a trajectory as indicated by an arrow in the drawing. When ions reach (collision) the detector 103, the detector 103 outputs an ion detection signal 1a having a large intensity in the polarity on one side as shown in the figure.

  The ion detection signal 1a is input to the data collection processing device 2 and the data is collected. In addition, since the signal waveform detected in each measurement is not always constant in the mass spectrometer 1, statistical data processing is required. Specifically, a plurality of measurements are performed and all data are integrated. This improves the measurement sensitivity (S / N ratio) of the ion detection signal. Here, the measurement of ions flying by one launch operation is called a TOF scan, and the measurement in which the TOF scan is repeated a plurality of times is called a TOF measurement.

  The TOF measurement is completed, and the integrated data 2a collected by the data collection processing device 2 is output to the input / output device 4 via the CPU 3. The measurement result is displayed as a mass spectrum 4a as shown in the figure, and the user can analyze the component contained in the sample from the intensity (voltage value) and the time (mass) of each spectrum.

  Next, an example of the configuration of the data collection processing apparatus according to the first embodiment will be described with reference to FIG. FIG. 2 shows the configuration of the data collection processing apparatus.

  The data collection processing device 2 according to the first embodiment includes a log amplifier 200 for amplifying the ion detection signal 1a from the mass spectrometer 1, and an A / A for converting the output waveform 200a from the log amplifier 200 into digital data. A D converter 201, a table memory 202 that performs data conversion in accordance with an output value 201a of the A / D converter 201, and an integration memory circuit 203 that performs integration processing of the measurement data 202a and stores the result in the memory. The

  Although not shown in FIG. 2, the A / D converter 201 is generally a differential signal input type, and can be a single input. Further, at the time of single input, the reference voltage of the input signal can be offset by applying a DC voltage to the terminal on the inverting input side. Further, a clock generator is mounted inside the data collection processing device 2, and the A / D converter 201, the table memory 202, and the integrating memory circuit 203 operate in synchronization with the master clock from the clock generator. It shall be.

  Next, an outline of the operation of the data collection processing apparatus according to the first embodiment will be described with reference to FIG. FIG. 3 shows an example of the relationship between the input voltage and the output voltage of the log amplifier.

When the measurement is started, the ion detection signal 1a from the mass spectrometer 1 is input to the log amplifier 200, and the signal is amplified according to the nonlinear input / output characteristics (FIG. 3) of the log amplifier 200. The relationship between the input voltage Vin and the output voltage Vout of the log amplifier 200 is
Vout = k · Log (Vin) (1)
It is represented by (Formula 1).

  The ion detection signal 1a amplified with the input / output characteristics shown in FIG. 3 is sampled at a certain time period by the A / D converter 201 and converted into voltage value data 201a at each time. This voltage value data is represented by the gradation value of the A / D converter 201. For example, when an 8-bit A / D converter is used, a value of 0 to 255 (decimal number) is output at each sampling time. Is done. In the conventional data collection processing device, the data after A / D conversion is integrated as it is, but the data 201a after A / D conversion in the first embodiment is a non-linear value amplified by the log amplifier 200. The integration process cannot be performed as it is.

  Therefore, in the first embodiment, the voltage value data 201a from the A / D converter 201 is subjected to reverse log (linear) conversion by the table memory 202. In the table memory 202, voltage value data for inverse log conversion calculated backward from the characteristics of the log amplifier 200 before measurement is stored, and the contents of the memory are stored with the voltage value data 201a from the A / D converter 201 as an address. By simply reading, voltage value data having linear characteristics before being amplified by the log amplifier 200 can be output.

  Next, an example of the contents of the table memory used in the first embodiment will be described with reference to FIG. FIG. 4 shows an example of the contents of the table memory (relationship between input voltage and output voltage).

  In the table memory 202, the address range of the memory is the same as the number of gradations (number of bits) of the A / D converter 201 to be used. In FIG. 4, an 8-bit A / D converter is assumed, and 0 to 255 are assumed. Address is prepared. The table memory 202 can be rewritten by the CPU 3, and voltage value data showing characteristics opposite to those in FIG. 3 is stored in advance at each address, and is output according to the output gradation of the input A / D converter 201. The voltage value is determined.

  That is, at the time of measurement, input data from the A / D converter 201 is read out as memory data with the address ADR (addresses 0 to 255), so that the input voltage value before being amplified by the log amplifier 200 without requiring calculation processing. Is obtained. For example, in the table memory shown in FIG. 4, when “255 (decimal number)” is received as the voltage value data 201a, “2000” [mV] stored in the address is output. Since the voltage value read by inverse log conversion in this way is a voltage value of a linear scale before being amplified by the log amplifier 200, integration processing can be performed.

  Next, the voltage value data linearly converted by the table memory 202 is input to the integration memory circuit 203 and stored in the integration memory. If data is already stored in the integration memory, the contents of the integration memory are read once, the current voltage value data is added, and then stored in the integration memory again. Here, when all sampling data of the ion signal for one time is collected, the TOF scan ends. Furthermore, the TOF scan can be repeated as many times as determined by the user, and the TOF measurement is completed when all the TOF scan times are performed.

  As described above, according to the data collection processing device 2 of the first embodiment, the log amplifier 200 having nonlinear input / output characteristics is used in the previous stage of the A / D converter 201, so that the A / D converter 201 is used. Measurement with a high dynamic range without increasing the number of bits, and a linear scale by reverse log conversion processing using the table memory 202 in which the signal 200a amplified by the log amplifier 200 is generated in advance. Since the data can be integrated by converting to the above value, it is possible to provide an ADC-type data collection processing device that realizes high measurement sensitivity by data integration processing simultaneously with measurement in a high dynamic range.

  Note that the data processing method used by the data collection processing device of the first embodiment can also be applied as a data processing method for a measuring device other than TOF-MS.

(Embodiment 2)
Next, the configuration of the data collection processing device and the data processing method according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 5 shows the configuration of the data collection processing apparatus.

  In addition to the configuration of the first embodiment, the data collection processing device 12 of the second embodiment is characterized by including a gain adjustment circuit 204 in the previous stage of the log amplifier 200, and other parts are described in the first embodiment. The configuration is the same as that of FIG.

  In the first embodiment, the input / output characteristics (FIG. 3) of the log amplifier 200 have been described. However, in the portion close to the lower limit of the input voltage range of the log amplifier, the gain changes rapidly with respect to the input voltage. A slight change in voltage causes a large change in gain, resulting in large variations in output voltage. On the contrary, in the portion close to the upper limit of the input voltage range, the change in the gain with respect to the input voltage is small and the output voltage is stabilized, but the output voltage changes greatly with a slight change in the input voltage during reverse log conversion.

  Therefore, in the second embodiment, as shown in FIG. 5, a gain adjustment circuit 204 is provided in the previous stage of the log amplifier 200 so that the input voltage of the log amplifier 200 can be adjusted. Therefore, for example, a range in which the gain variation of the log amplifier 200 is small can be selected.

  In the second embodiment, when the TOF measurement is started, the ion detection signal 1a from the mass spectrometer 1 is input to the gain adjustment circuit 204. The gain adjustment circuit 204 is controlled by the CPU 3 and can amplify the input signal with an arbitrary gain amount set by the user. At this time, the CPU 3 adjusts the output signal 204 a from the gain adjustment circuit 204 within the input voltage range of the log amplifier 200, and the output of the log amplifier 200 is within the input voltage range of the A / D converter 201. Adjust the gain so that it does not exceed.

  The signal 204 a whose amplitude is adjusted by the gain adjustment circuit 204 is input to the log amplifier 200 and amplified according to the nonlinear input / output characteristics of the log amplifier 200. The amplified ion detection signal 200 a is sampled by the A / D converter 201 as in the first embodiment, subjected to inverse log (linear) conversion by the table memory 202, and then integrated by the integration memory circuit 203.

  As described above, according to the data collection processing device 12 of the second embodiment, the log amplifier 200 is adjusted by adjusting the input voltage of the log amplifier 200 by the gain adjustment circuit 204 provided in the previous stage of the log amplifier 200. Since the use range of the input / output characteristics can be adjusted to an arbitrary range, in addition to the effects described in the first embodiment, an ADC type data collection processing device that realizes higher measurement accuracy is provided. it can.

(Embodiment 3)
Next, the configuration of the data collection processing device and the data processing method according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 6 shows the configuration of the data collection processing apparatus.

  In addition to the configurations of the first and second embodiments, the data collection processing device 22 of the third embodiment can detect the maximum value from the digital data 201a sent from the A / D converter 201 during calibration. Signals different from the peak value detection circuit 205, the table memory 207 that can write the data 3c from the CPU 3 during calibration, the internal signal selector 206 that selects the input data path of the table memory 207, and the data collection processing device 22 As an input device, an arbitrary waveform generator 5 and an external signal selector 6 for switching an input signal of the data collection processing device 22 are provided.

  Other configurations are the same as those in the first and second embodiments. The arbitrary waveform generator 5 shown in FIG. 6 is a waveform generator that can set the period of the output signal, the type of waveform (sine wave, rectangular wave, etc.), and the voltage value (effective value or maximum value). The apparatus is not limited.

  The table memory 207 in the third embodiment is a memory that can be rewritten by calibration, but in which data can be directly written from the CPU 3 as in the first and second embodiments.

  In the table memory 202 used in the first and second embodiments, the voltage value data for reverse log conversion obtained from the characteristics of the log amplifier 200 is stored in advance, but in the third embodiment, before the actual measurement. Then, by performing measurement of a known waveform through the log amplifier 200, calibration for generating the table memory 207 for reverse log conversion is performed.

  This calibration is performed before the TOF measurement, and before and after being amplified by the log amplifier 200 by measuring the input / output characteristics of the log amplifier 200 using a signal having a known voltage value generated from an external device. A conversion table for reverse log conversion can be generated from the voltage value data.

  The flow of data processing during calibration according to the third embodiment will be described with reference to the flowchart of FIG. FIG. 7 shows a processing flow of table memory calibration.

  When calibration is started, first, the CPU 3 controls the external signal selector 6 outside the apparatus, and switches the input of the data collection processing apparatus 22 to the signal path b from the external arbitrary waveform generator 5. At the same time, the internal signal selector 206 of the data collection processing device 22 is switched to the b side so that the signal from the peak value detection circuit 205 is input (processing 700). Next, in this calibration, the A / D converter 201 is a single input, an offset voltage (DC voltage) is applied to the terminal on the inverting input side, a TOF scan is performed once, and the A / D when no signal is input. The offset voltage adjustment is repeated until the output voltage value (gradation value) of the converter 201 becomes 0 [V] (processing 701).

  Next, the CPU 3 controls the arbitrary waveform generator 5 to generate a signal 5 a having a known voltage value (in the present embodiment, a single frequency sine wave) and inputs it to the data collection processing device 22. (Process 702). Further, the CPU 3 transmits the maximum voltage value data 3c of the sine wave 5a set in the arbitrary waveform generator 5 to the table memory 207 in the data collection processing device 22 (processing 703).

  Next, the CPU 3 starts a TOF scan for calibration (process 704). The sine wave 6a input to the data collection processing device 22 is amplified by the log amplifier 200 and sampled by the A / D converter 201 (processing 705). The peak value detection circuit 205 that has received the digital data (gradation value) 201a from the A / D converter 201 detects digital data indicating the maximum voltage value from all the data received until the TOF scan is completed. (Process 706).

  After the TOF scan ends (process 707), the table memory 207 uses the maximum voltage value data 205a from the peak value detection circuit 205 as an address, and stores the voltage value data 3c sent from the CPU 3 at the address (process 708). ).

  In this calibration, steps 702 to 708 are repeated while changing the voltage value of the sine wave 5a generated from the arbitrary waveform generator 5 (step 711) until data of all addresses in the table memory 207 can be acquired.

  However, if the range of the voltage value of the waveform to be measured during normal measurement is known and it is known that it is not necessary for all addresses in the table memory 207 to contain data, the CPU 3 checks the contents of the memory. Calibration end determination may be performed.

  In the above flow, the number of TOF scans at the time of calibration is one, but the accuracy of the maximum voltage value measurement can be improved by obtaining the average value from the integrated maximum voltage value data stored in the integration memory as N measurements. Can be increased.

  When data is written to all addresses in the table memory 207 and calibration is completed (process 709), the CPU 3 switches the external signal selector 6 and the internal signal selector 206 to the a side, and the input signal of the data collection processor 22 is The signal from the mass spectrometer 1 is used, and the input data path of the table memory 207 is the signal from the A / D converter 201 (process 710). Subsequently, the same TOF measurement as in the first and second embodiments is performed. Can be implemented.

  As described above, according to the data collection processing device 22 in the third embodiment, the input / output characteristics of the log amplifier 200 are measured using a signal having a known voltage value generated from an external device, By acquiring voltage value data before and after being amplified by the log amplifier 200, a conversion table for reverse log conversion based on the actual characteristics of the log amplifier 200 used in the data collection processing device 22 is generated. It becomes possible to measure with higher accuracy.

  In the calibration according to the third embodiment, the method of acquiring data of all addresses in the table memory 207 has been described. However, among the input / output characteristics of the log amplifier 200, several input / output voltages are calibrated. The CPU 3 may perform interpolation processing from the obtained data and write the voltage value calculated by the processing directly into the table memory 207.

  The calibration may be performed for each measurement, or the contents of the table memory once acquired can be stored in the CPU as calibration data, and the calibration data can be loaded before measurement. It is.

  In FIG. 6, the switching control of the signal path is performed by the CPU 3, but the switching control may be performed by the control circuit 208 provided in the data collection processing device 32 as shown in FIG.

  In FIGS. 6 and 8, the external signal selector 6 is used to switch the path of the input signal, but the cable may be changed manually.

(Embodiment 4)
Next, the configuration of the data collection processing device and the data processing method in Embodiment 4 of the present invention will be described with reference to FIG.

  FIG. 9 shows a configuration from the signal input unit to the table memory of the data collection processing device.

  The data collection processing device 42 according to the fourth embodiment includes a log amplifier 200 and a gain adjustment circuit 209 that are configured in parallel before the A / D converter 201, and a switching circuit 210 for switching between two types of amplifiers. , A switching circuit 211 for switching the path of the voltage value data 201a after A / D conversion is provided. The configuration of other parts is the same as in the first to third embodiments.

  The gain adjustment circuit 209 is an amplifier having linear gain characteristics, and an arbitrary gain amount can be set by a gain setting signal 208c from the control circuit 208. The gain adjustment circuit 209 and the log amplifier 200 are configured in parallel before the A / D converter 201, and their outputs are input to the switching circuit 210. The switching circuit 210 can switch an amplifier to be used by a switching signal 208d from the control circuit 208.

  Similarly, the switching circuit 211 can switch whether the voltage value data after A / D conversion is input to the table memory 207 or input to the integration memory circuit as it is, according to the switching signal 208d from the control circuit 208.

  Here, when the log amplifier 200 is selected, as described in the first to third embodiments, voltage value conversion is performed using the reverse log conversion table memory 207 generated based on the characteristics of the log amplifier 200. (Reverse log conversion mode).

  On the other hand, when the gain adjustment circuit 209 is selected, the amplifier selection signal 208d output from the control circuit 208 selects the mode (through mode) in which the input voltage value is output as it is without using the reverse log conversion table. The Although a path for directly inputting voltage value data to the integrating memory circuit is provided in FIG. 9, a table memory having the same input value and output value may be used.

  The output of the arbitrary waveform generator 5 used for the calibration of the table memory 207 is ideally “set voltage 208b = output voltage 5a”. However, the set voltage is actually set by the error of the generator itself or loss of the cable or the like. An error occurs in the output voltage. When accuracy is required for the absolute value of the converted voltage stored in the table memory 207, it is necessary to correct the output characteristics of the arbitrary waveform generator itself.

  Therefore, in the fourth embodiment, the gain of the gain adjustment circuit 209 is set to 1 time, and the absolute voltage value is measured while varying the amplitude of the output signal 5a of the arbitrary waveform generator 5, whereby the arbitrary waveform generator 5 Gain (input / output) characteristics can be obtained. At the time of calibration of the reverse log conversion table memory described in the third embodiment, it is possible to perform calibration with higher accuracy by setting a voltage value corrected based on this gain characteristic.

  As described above, according to the fourth embodiment, since the log amplifier 200 having the nonlinear gain characteristic and the gain adjustment circuit 209 having the linear characteristic are provided in parallel, the high dynamic using the log amplifier 200 is achieved. The range data integration process and the highly accurate data integration process using the gain adjustment circuit 209 can be switched depending on the measurement object.

  Furthermore, the ability to switch and use amplifiers having different gain characteristics enables high dynamic range measurement or high accuracy measurement with a single device.

  In addition, the gain characteristics of the external arbitrary waveform generator 5 used for calibration of the table memory 207 can be calibrated by measurement using the gain adjustment circuit 209.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is applied to a data collection processing apparatus for a measuring apparatus using an A / D converter, and is particularly effective for an ADC type data collection processing apparatus used in an analysis apparatus such as TOF-MS.

It is a figure which shows the outline | summary of a structure and operation | movement of a mass spectrometer to which the data collection processing apparatus of this invention is applied. In the mass spectrometer of Embodiment 1 of this invention, it is a figure which shows the structure of a data collection processing apparatus. In the mass spectrometer of Embodiment 1 of this invention, it is a figure which shows the relationship between the input voltage of a log amplifier, and an output voltage. In the mass spectrometer of Embodiment 1 of this invention, it is a figure which shows the content (relationship between an input voltage and an output voltage) of the table memory. It is a figure which shows the structure of a data collection processing apparatus in the mass spectrometer of Embodiment 2 of this invention. It is a figure which shows the structure of a data collection processing apparatus in the mass spectrometer of Embodiment 3 of this invention. It is a figure which shows the processing flow of the calibration of a table memory in the mass spectrometer of Embodiment 3 of this invention. It is a figure which shows an example of a structure of a data collection processing apparatus in the mass spectrometer of Embodiment 3 of this invention. In the mass spectrometer of Embodiment 4 of this invention, it is a figure which shows the structure from the signal input part of a data collection processing apparatus to a table memory.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mass spectrometer, 2, 12, 22, 32, 42 ... Data collection processing device, 3 ... CPU, 4 ... I / O device, 5 ... Arbitrary waveform generator, 6 ... External signal selector, 101 ... Introduction part, DESCRIPTION OF SYMBOLS 102 ... TOF part, 103 ... Detector, 104 ... Ion implantation signal generator, 200 ... Log amplifier, 201 ... A / D converter, 202, 207 ... Table memory, 203 ... Integration memory circuit, 204 ... Gain adjustment circuit 205 ... Peak value detection circuit, 206 ... Internal signal selector, 208 ... Control circuit, 209 ... Gain adjustment circuit, 210, 211 ... Switching circuit.

Claims (7)

A data collection processing device using an A / D converter,
Log amplifier that amplifies the input analog signal with nonlinear input / output characteristics,
An A / D converter for sampling an output signal from the log amplifier;
A table memory that reverse-log converts digital data output from the A / D converter into linear scale data;
An integration memory circuit for storing the data converted into the linear scale while integrating;
A data collection processing apparatus comprising: The data collection processing device according to claim 1,
A data collection processing apparatus further comprising a gain adjustment circuit capable of adjusting a gain of an input signal before the log amplifier. The data collection processing device according to claim 1,
A gain adjustment circuit having a linear gain characteristic in parallel with the log amplifier, and a first switching circuit, in front of the A / D converter;
A second switching circuit at a subsequent stage of the table memory;
A data collection processing apparatus, wherein the data collection processing apparatus is switched to the log amplifier or the gain adjustment circuit. In the data collection processing device according to any one of claims 1 to 3,
A data collection processing apparatus characterized in that a known voltage value is inputted to the log amplifier to perform measurement, and the set voltage value and voltage value data after A / D conversion can be stored in the table memory. In the data collection processing device according to any one of claims 1 to 4,
A data collection processing apparatus, wherein the data in the table memory can be rewritten to an arbitrary value by a CPU controlling the data collection processing apparatus. In the data collection processing device according to any one of claims 1 to 5,
The data collection processing apparatus is used in a time-of-flight measurement type mass spectrometer. The data collection processing device according to claim 6,
The time-of-flight mass spectrometer is operated by an introduction unit that ionizes a sample to be analyzed, a TOF unit that accelerates by applying a voltage to the ionized sample and accelerates ions toward a detector. A data collection processing apparatus, comprising: a detector that detects the detected ions; and an ion ejection signal generator that generates an ion ejection signal that determines a timing for accelerating the ions.

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